【列表5.5】從一個(gè)GUI程序中建立一個(gè)子進(jìn)程。
procedure TForm1.Button1Click(Sender: TObject);
var
   pid : pid_t;
   i : integer;
   open_max : integer;
   fname : String;
begin
   pid := fork:
   case pid of
       -1 : ShowMessage ('Error in fork');
       0:
       begin
          { Child closes all file descriptors but stdin, stdout, and stderr}
          open_max := sysconf ( _SC_OPEN_MAX);
          for i := stderr+1 to open_max-1 do
             fnctl (I,F_SETFD, FD_CLOEXEC);
          fname := GetModuleName (0);
          execlp (PChar (fname). PChar (fname). nil);
       end;
       else
          Memo1. Lines.Add (Format ('Forked to child pid %d', [pid]));
     end;
  end;